1918.] NATURAL SCIENCES OF PHILADELPHIA. 141 



A NEW CHARACIN FROM PARAGUAY, 

 BY HENRY W. FOWLER. 



Recently the Academy received a small collection from Senor 

 A. De W. Bertoni, secured at Puerto Bertoni, Paraguay. As this 

 contains several interesting fishes : Otocinclus vittatus Regan, Parodon 

 paraguayensis Eigenmann, Phalloceros caudimaculatus (Hensel) and 

 the Characin belonging to the Tetragonopterinae described below, 

 this note has been prepared. The Academy is indebted to Senor 

 Bertoni for these interesting gifts to its Museum. 



BERTONIOLUS gen. nov. 



Type, Bertoniolus paraguayensis sp. nov. 



Preventral region evenly convex. Maxillary slips below preorbital 

 or only about half its upper edge shielded. Upper teeth 5 each side 

 in inner row as in Moenkhausia, and outer series in row parallel. 

 Mandibular teeth uniserial. Upper lip covers premaxillary teeth. 

 Gill-rakers lanceolate. All scales cycloid. Predorsal scales uniform 

 in size. Preventral with normal scales. Anal with rather broad 

 basal scaly sheath its entire length. Caudal base covered with 

 large scales. Lateral line complete, slightly decurved, parallel 

 with rows of scales below. 



Allied to Moenkhausia Eigenmann and Markiana Eigemnann. 

 From the former it is distinguished by the second suborbital in 

 contact mth the preopercle below, a point in agreement with Knodus. 

 It differs from Knodus in the 5 teeth each side in the inner upper 

 row, a character in agreement with Moenkhausia. Markiana 

 Eigenmann somewhat resembles it, but the anal is more scaly and 

 its unequal short lobed caudal is quite different. In Bryconamericus 

 the caudal scales are small, not large as in this genus. 



One species in the Parama basin. (For Senor A. De W. Bertoni, 

 the accomplished naturalist of Peurto Bertoni, Paraguay.) 



Bertoniolus paraguayensis sp. nov. 



Head 3|; depth 2f ; D. ii, 9; A. ii, 27; P. i, 11; V. i, 7; scales 43 

 in 1. 1. to caudal base and 3 more on latter; 9 scales above 1. 1. and 10 

 below; about 17 predorsal scales; head width 2 in its length; head 

 depth over eye center 1|; snout 3^; eye oh; maxillary 21; interorbital 



